Endoscopy is a mature class of surgery that came into wide use in the 1960s. Endoscopes currently exist in an array of different forms and are suitable for use in a wide variety of surgical procedures. Even though endoscopes may be highly specialized for a particular procedure, they all contain the same basic component systems. Most endoscopes comprise either a camera at the distal tip or an objective optical system, which captures a single image or view of the surgical area. Together with the objective optical system, the endoscope comprises a relay optical system, which carries the image from the distal to proximal end of the device, and an eyepiece or camera system (or both) to view the transmitted image. Light to illuminate the surgical scene is delivered via optical fibers or waveguides that are integral to the endoscope. The endoscope may also contain working channels or incorporate treatment options such as laser delivery. All of these elements are contained within an outer sheath that may be made from rigid or flexible materials. The endoscope itself may be rigid, semi-flexible, or flexible, and may comprise components that allow it to be actively bent in one or more directions at its distal tip.
Endoscopes comprising articulation sections that can be bent from and returned to a straight configuration, thus allowing the distal end of the tip to be pointed at an angle to the axis of the endoscope are known in the prior art. In U.S. Pat. No. 5,762,067 is disclosed an endoscope comprising a two-way articulation section, i.e. one that can be bent and unbent in a single plane. A four-way articulation section, i.e. one that can be bent and unbent in two mutually perpendicular planes, is disclosed in U.S. Pat. No. 6,704,898. An endoscopic device comprising elements of a stapling assembly attached to each end of an articulation section is described in U.S. Pat. No. 6,872,214 by the applicant of the present application; the description of which, including reference cited therein, is incorporated herein by reference in its entirety.
All endoscope articulation sections are comprised of a chain of separate elements usually referred to as links or vertebra. Neighboring links are generally connected together by a pin through slots or holes in their ends, although other arrangements are known. For example, in U.S. Pat. No. 5,762,067 the articulation section is comprised of rings separated by balls and held together by cables that pass through the rings and balls. In U.S. Pat. No. 3,060,972 is disclosed an articulation section in which each vertebra is comprised of two parts sections having the shape of one half of a cylinder cut be a plane containing the longitudinal axis of the cylinder. The two halves of the cylinder axe held together by the bending cables. In all cases, neighboring links are caused to pivot about the connecting pins or balls by pulling on cables and the accumulated rotation of all the links gives the total bending angle of the articulation section.
All of the prior art arrangements share a common feature, i.e. the cables, electrical wires, optical fibers, irrigation lines, etc. pass through the hollow interior of the links of the articulation section on their way from the proximal end of the endoscope to the distal tip. There are at least two negative consequences of this arrangement. The first is that the various cables, lines, fibers, etc. tend to move around inside the links when the articulation section is activated as a consequence of the difference in length between the straight and bent configurations. In extreme cases, this freedom of motion can result in kinking or even breakage of the thin fibers or wires. The second consequence is that to replace a broken cable, wire, etc. or a worn link, pin, etc. it is necessary to take the entire vertebra section apart and reassemble it, which is a time consuming and expensive process.
It is a purpose of the present invention to provide an articulation section that overcomes the deficiencies of the prior art.
Further purposes and advantages of this invention will appear as the description proceeds.